Buckfever

What about long run reliability of the diesel versus the gas engine?

Suzy991

Reliability of diesel engines has always been very good. Our neighbours have an old 2002 Audi A8 with a 3.0 TDI V6, that has done more than 600,000km (370,000 miles) without any problems. Just the regular service at the dealership.
I did 104,000km in 14 months in my SQ5 and needed (regular) service only twice.

As long as an engine gets its regular maintenance, it will easily last 250,000 miles minimum, no matter if it is a petrol or diesel engine. It would be the last thing I'd worry about.

Louis.E

Late model audis are a sweet ride indeed.

Buckfever

The problem here apparently was that the Bosch diesel pump was not equipped to deal with the poor diesel fuel quality. Apparently 3 revisions, latest late 2010. Also manufacturing quality of the entire system was suspect. Incidence has dropped precipitously since then. I think that a Leipzig build would give me more confidence.

I just calculated that I average over 26,500 miles yearly. If anyone should get the diesel it's me.

Suzy991

Is diesel quality that bad in the US?

And indeed... With that milage, a diesel is the best option in a car like that. No doubt about it.

fincher

Depends on the location. Illinois has B5 most places and some go up to B20. I usually fuel with no bio...there's a place near me. I do use B5 sometimes. I do use an additive every few fill ups and when we have sub-zero weather I use Power Service white bottle. The fuel here is not as good but I think VAG has now accounted this for this. I have 45k on my 28-month old TDI and have had no issues.

speed21

All things being equal the diesel will outlast the petrol. You only need to compare the wear cycles...

And any talk of high pressure fuel pumps is moot in the sense they both use those and high pressure injectors.... Again, wear cycles and all things being equal in terms of operation, servicing and environment the diesel will live longer. Only exception would be where a diesel is small capacity and overly reliant upon turbocharging to achieve a comparable output. (i.e a 2 litre 4 cyl twin turbo diesel vs a 3 litre turbo petrol pulling the same weight car). This of course is not applicable if comparing a 3 litre turbo diesel to a 3 litre turbo petrol.

Given the industry I'm in its a very funny topic for me when I hear people speculate on how long an engine is going to last....especially a new Porsche buyer. Too funny...

PS love the bit about getting diesel on the hands as a reason to stay away lol. Any type of fuel on your hands is bad and will be hard to remove the smell. Plus service stations these days all have towel dispensers or gloves and if they don't chances are their fuel is also not much good. Best to avoid these types of budget operated stations that don't offer the basics and/or appear to be dodgy.

speed21

I would agree with that. A diesel outshines a petrol on a long run in a number of ways. To take a petrol over a diesel in this type of vehicle in these types of operating conditions is madness...sorry.

In so far as revisions to fuel pumps, that can apply to any engine which uses a HPP. Same with a faulty batch of something....can happen to anything no matter where it is made or assembled. I see there is a lot of jumping shadows going on here in a bid to justify ones position over getting one over the other. Not necessary. The basic facts regarding petrol vs diesel will always remain same so it comes purely down to individual choice, and once that choice is made just live with it for good bad or otherwise. We can all make mistakes. Far too much emphasis is being placed on performance claims based on zero to 100 as being a prime motivator when in most real word driving situations it is actually the "in gear pull" and the ability to shift the weight quickly on the move without using copious amounts of fuel in that process that wins the day for most owners of these types of vehicles. New or used.

Just goes to show how effective marketing can be. Promote a "sportier" truck, put a Porsche badge on it and people will buy them by the boat load. Let em worry about all that fuel later..

The only sound reason why not to buy a diesel over a petrol is in the event where the car will mostly see a lot of very short runs in built up areas.

Buckfever

A heartfelt thank you to all who have helped me here. The sense of community and generosity is exemplary. IMO